Pulse multiplier for surface operated single tube pump

Abstract

A device for multiplying the effective pulsations on a column of liquid which operates an underground pump. The pulsations are created by a pulse generator at the ground surface and are transmitted through the column of liquid being pumped to operate the underground pump. The pulse multiplier is interposed in the single tube at the ground surface and is effective to partially divert the flow of liquid from the tube to a receiving tank when gas pockets in the column of liquid reach a predetermined degree and relieve the column of the gas pockets by by-passing the liquid under pulsations from the pulse generator back to the receiving tank.

What is claimed is: 
     
       1. In a single tube surface operated pump including a. an underground pump that is operated by pulses on a column of the liquid being pumped,   b. a tube extending from said pump to a ground surface and containing said column of liquid,   c. a receiving tank at said ground surface, and   d. a pulse generator comprising: I. a cylinder having a lateral port communicating with said receiving tank,   Ii. a piston reciprocal in said cylinder, and   Iii. power means for reciprocating said piston, a pulse multiplier for increasing the pulses created by said generator which are effective on said column of liquid, said pulse multiplier being connected at one side to the lower end of said cylinder, at the other side to said receiving tank and comprising:       e. a casing having a bore one end of which is connected to the upper end of said tube,   f. a first lateral port in said casing to which a conduit from the end of said cylinder is connected,   g. a second lateral port in said casing and connected to a conduit from said receiving tank,   h. a piston reciprocal in said casing,   i. a spring in said casing biasing said piston into a position in which there is a direct flow of the liquid of said column from said first lateral port to said cylinder under the influence of said underground pump which is operated by pulses created by said pulse generator,   j. surfaces on said piston in the casing which are exposed to gas pockets in said column of liquid and tending to displace said piston from its position providing said direct flow, and   k. a yieldable detent holding said piston in said position until the pressure of said gas pockets on said piston surface reaches a predetermined degree, whereupon said detent yields and said piston in said casing is moved by gas pressure into a position in which a portion of the liquid from said column is diverted to the second lateral port and is delivered to said receiving tank, said diverted liquid entraining gas in said casing and thereby relieving the gas pressure to permit said spring to return the piston in said casing into its position providing said direct flow of liquid.     
     
     
       2. The pulse multiplier of claim 1 in which said bore is counterbored intermediate its ends, the counterbore further enlarged centrally thereof and a passage of reduced diameter extends from the end of the bore to the end of the casing remote from the end connected to said tube, and the piston includes a lower section snugly slidable in said bore, a piston head snugly slidable in said counterbore, and a piston rod snugly slidable in said passage. 
     
     
       3. The pulse multiplier of claim 2 in which said spring is an expansion spring coiled about said piston rod and having one end seated in a recess in the end of said piston head with its other end abutting a surface at the end of and normal to said counterbore. 
     
     
       4. The pulse multiplier of claim 2 in which the lateral ports in the casing are offset with respect to each other and the lower piston section is formed with an external annular recess of a diametric length spanning the offset between said lateral ports. 
     
     
       5. The pulse multiplier of claim 4 in which the piston in the casing has an axial passage extending from the lower end of the lower piston section to a point spaced from the end of said piston head, radial passages in said lower piston section connecting said annular recess and said axial passage, and a diametric passage in said piston head at the end of said axial passage. 
     
     
       6. The pulse multiplier of claim 2 in which the piston rod has an end portion of reduced diameter with a curved shoulder between said piston rod and said rod and said end portion, a radial passage in said casing opening onto said shoulder when said piston is in said position of direct flow, and the detent takes the form of a spring biased ball in said passage engaging said shoulder. 
     
     
       7. The pulse multiplier of claim 3 in which the casing comprises lower and upper casing parts secured in assembled relation by screw bolts with the upper casing part being formed with a socket constituting an extension of said counterbore, at the radial passage for said ball detent.